Multifunctional quasi-solid-state zinc-ion hybrid supercapacitors beyond state-of-the-art structural energy storage

Structural energy storage devices offer both electrochemical and mechanical performance in a single multifunctional platform, making them promising for weight-and/or volume-restricted applications such as electric vehicles, aircraft, and satellites. However, the development of state-of-the-art multifunctional energy storage is predominately hindered by poor energy density. Other parameters that influence the mechanical and electrochemical properties are also neglected, such as temperature, safety, etc. Herein, we assembled the first freeze-resistant, multifunctional quasi-solid-state zinc-ion hybrid supercapacitor (ZIHSC) using mechanically-strong hot-drawn, highly-porous nitrogen-doped carbon nanofibers as the load-bearing cathode and zinc foil as a paintable, malleable, low cost, highly safe, and robust anode. Considering the novel "two-birds-one-stone " strategy, the as-prepared multifunctional ZIHSCs outperform state-of-the-art structural energy storage devices in terms of a combination of energy storage and load-bearing capability. The structural ZIHSCs offer a battery-level gravimetric energy density of 113.1 Wh/kg, areal energy density of 300.0 mWh/cm(2), strength of 308 MPa, Young's modulus of 14.40 GPa, toughness of 1.82 MJ/m3, and cycling stability over 7500 cycles. In addition, multifunctional ZIHSCs offer outstanding electrochemical and mechanical performance under a wide range of temperatures from cryogenic (-25 ;C) to ambient ( thorn 25 C) conditions. (c) 2022 Elsevier Ltd. All rights reserved.